Body Surface Area Calculator
Calculate your body surface area (BSA) in m² using the Du Bois and Mosteller formulas — commonly used in clinical drug dosing and medical assessments.
About Body Surface Area
Body surface area (BSA) is the measured or calculated surface of the human body. Unlike weight or BMI, BSA has a strong physiological correlation with many body functions — particularly cardiac output, renal clearance, and metabolic rate per unit of body surface. This is why BSA is the standard basis for dosing chemotherapy agents, where toxicity is closely related to the surface area exposed. Oncologists use BSA to calculate doses of drugs like cisplatin, carboplatin, and doxorubicin, ensuring appropriate dosing regardless of a patient's absolute body size.
The Du Bois formula, developed in 1916 by Delafield Du Bois and Eugene Floyd Du Bois, is one of the oldest and most widely cited methods. It was derived from nine subjects and has been the clinical standard for decades: BSA = 0.007184 × H0.725 × W0.425. The Mosteller formula (1987) is a simplified alternative — BSA = √(H × W / 3600) — that is easier to compute and widely used in clinical practice because it gives very similar results to Du Bois with minimal calculation. Both formulas use height in centimeters and weight in kilograms and return BSA in square meters.
BSA is also used in burn medicine to estimate the percentage of skin affected (following the "rule of nines"), in calculating pediatric drug doses, and in assessing cardiovascular parameters like cardiac index (cardiac output normalized to BSA). Understanding your lean body mass alongside BSA can be valuable — visit our Lean Body Mass Calculator to compare multiple estimates. For general health tracking, consider pairing BSA data with Ideal Weight calculations to get a comprehensive picture of your body composition.
Formula Reference
| Formula | Equation | Year |
|---|---|---|
| Du Bois | 0.007184 × H⁰·⁷²⁵ × W⁰·⁴²⁵ | 1916 |
| Mosteller | √((H × W) / 3600) | 1987 |
H = height in cm, W = weight in kg, result in m²
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For a related calculation, use Ideal Weight Calculator to calculate ideal body weight using Devine, Robinson, Miller, and Hamwi formulas. Alternatively, use Lean Body Mass Calculator to calculate lean body mass using Boer, James, and Hume formulas from weight and height.